1. Field of the Invention
The present invention relates to a technique related to a configuration of a differential device that is a differential device having a disconnect mechanism with which a power transmission member for transmitting a drive force only to auxiliary drive wheels in a four-wheel drive state is separated (disconnected) from the auxiliary drive wheels in a two-wheel drive state.
2. Description of the Related Art
In a four-wheel drive vehicle in which a selection is made between a two-wheel drive state of transmitting a drive force from a drive power source to left and right main drive wheels and a four-wheel drive state of transmitting a drive force from the drive power source to left and right auxiliary drive wheels in addition to the main drive wheels, a differential device is known that has a disconnect mechanism with which a power transmission member for transmitting a drive force only to the auxiliary drive wheels in the four-wheel drive state is separated from the auxiliary drive wheels in the two-wheel drive state. For example, this corresponds to a differential device described in WO 2010/019641 A2.
The differential device described in WO 2010/019641 A2 has a control coupling (multiplate clutch) disposed on an axle between a differential gear device and one of left and right auxiliary drive wheels, and separates the differential gear device from the one of the left and right auxiliary drive wheels by using the control coupling in the two two-wheel drive state, thereby separating from the auxiliary drive wheels a power transmission member, for example, a propeller shaft for transmitting a drive force only to the auxiliary drive wheels in the four-wheel drive state.